• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.7
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• pp.9-17
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• 2000

Determining the position and velocity of mobiles is an important issue for efficient handoff and channel allocation in microcell structure. Our early work proposes a technique for estimating the mobile location in the microcellular architecture. This process is based on the three step position estimation which determines the mobile position by gradually reducing the area of the mobile position. Using three step method, the estimator first estimates the locating sector in the sector estimation step, then estimates the locating zone in the zone estimation step, and then finally estimates the locating block in the block estimate step. But this scheme is prone to errors when the mobile is located in the boundary of sectors or tracks. In this paper we propose the enhanced scheme to reduce the estimation error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.370-379
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• 2018

The Korean government announced plans for the International Science Business Belt as a spatial area for promoting the linkage between scientific knowledge and commercialization in 2009. R&D and entrepreneurial activities are essential for the success of the International Science Business Belt. In particular, prioritizing the types of businesses is critical at the cluster establishment stage in that this largely affects the features and development of clusters comprising the International Science Business Belt. This research aims to predict the entry and growth of firms that specialize in four industrial clusters, including Big Science Cluster, Frontier Cluster, ICT Cluster, and Bio-Healthcare Cluster. For this purpose, we employ the Swann & Prevezer's industrial clustering model to identify sectors that affect the establishment and growth of industrial clusters in the International Science Business Belt, focusing on ICT, Bio-Healthcare and Frontier clusters. Data was collected from the 2014 Korean Innovation Survey (KIS) and University Alimi for the ICT cluster, 2014 National Bio Industry Survey and University Alimi for the Bio-Healthcare Cluster, and the 2015 National Nano Convergent Industry Survey and Annual Report of Nano Technology for the Frontier cluster. Empirical results show that the ICT service sector, bio process/equipment sector, and Nano electronic sector promote clustering in other sectors. Based on the analysis results, we discuss several policy implications and strategies that can attract relevant firms for the development of industrial clusters.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.345-348
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• 2002

본 연구에서는 128개의 능동소자로 구성된 convex형 초음파 탐촉자를 회전시켜 3차원 입체영상을 구현 할 수 있도록 하는 구동부를 설계 및 제작하여, 3차원 입체 영상 진단용 초음파 섹터 트랜스듀서를 개발하였다. 탐촉자는 중심주파수 4.5Mhz, 대역폭 $66\%$로 제작되었으며, 구동부는 탐촉자의 축을 스텝모터와 평기어를 이용해 회전시킴으로써 3차원 입체영상을 획득할 수 있게 고안하였다. 그리고 피부와 유사한 고분자재료를 사용하여 탐촉자의 회전반경과 동일하게 음향커버를 설계 및 제작하였다. 제작된 초음파 섹터 트랜스듀서는 정밀한 각도 제어 및 구조적 안정성이 확보되었음을 확인 할 수 있었다.

• The Journal of the Acoustical Society of Korea
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• v.21 no.8
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• pp.766-771
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• 2002

In this study, we have developed a 3-dimensional diagnostic ultrasonic sector probe using a convex type ultrasonic probe with 128 active elements. The probe was made to operate at the center frequency of 4.5㎒ with the bandwidth of 66%. The driving part was designed to rotate the axis of the convex probe by means of a step motor equipped with reduction gears and spur gears attached to the motor so that the probe could enable us to acquire a series of 2-dimensional images to construct a 3-dimensional image. Acoustic cover of the probe was made of polymers to have the same radius of rotation as that of the convex probe. The controllability of the rotation angle and the structural stability of the probe were confirmed through experimental 3-dimensional images obtained using the developed 3-dimensional sector probe.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.29-35
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• 2010

The cooperative transmission between sectors in next generation communications standards, e.g., 3GPP LTE-Advanced and IEEE 802.16m, has become an important research issue. Hence methods to decide the optimal antenna tilting angle in cooperative transmission between sectors are needed. This paper proposes methods to decide the optimal antenna tilting angle in cases of non-cooperative and cooperative transmissions between sectors. The proposed methods use an objective function that maximizes the cell average log rate or the cell average rate for users distributed uniformly within the radius of the sector. Also, the objective function which maximizes the cell average rate determined by adaptive modulation and coding (AMC) used in actual cellular systems is considered. When the cell average rate becomes the objective function, the system rate efficiency increases significantly for both cooperative and non-cooperative transmission. When the cell average log rate and the AMC rate become the objective functions, an optimal antenna tilting decision method which effectively increases the efficiency of cell boundary users is discussed.

• 한국벤처창업학회:학술대회논문집
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• 2006.11a
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• pp.221-249
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• 2006

최근 세계는 경제블록화가 급속한 진행되는 한편 EU가입국의 확대, 중국의 WTO 가입을 비롯하여 정보통신기술의 발달에 따른 무역 패러다임의 변화 등으로 급격한 전환기를 맞이하고 있다. 이러한 무역환경의 변화에 신속히 대처하기 위해 우리나라는 폭넓은 무역지원정책을 추진하고 무역관리체계를 정비하고 있음에도 불구하고 기대만큼의 실효를 거두지 못하고 있으며, 중소기업들은 국내외 경기의 지속적인 침체로 점차 해외경쟁력을 잃어가고 있다. 수출진흥을 위한 정책지원 전략은 무역환경의 변화에 대한 정확한 인식을 바탕으로 하여 무역중소기업의 무역마케팅구조를 근본적으로 개선하는데 궁극적인 목표를 두고 현장실무지원 중심으로 체계적이고 종합적인 수출지원사업 실행방안을 마련하는 일이 우선시 되어야 할 것이다. 따라서 본고에서는 국내 수출중소기업들을 대상으로 설문조사를 실시하여 이를 바탕으로 정부 수출지원사업 활용현황과 무역진흥정책 추진에 따른 향후과제를 검토 분석해보고, 나아가 기업들과 정부 유관기관과의 협력방안을 도출하는데 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.451-456
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• 2005

This paper proposes an evaluation model to assessment of development and operation for maritime leisure in Mokpo Port.. The proposed model is combination of SWOT(Strength, Weakness, Opportunity, Threat) and AHP(Analytic Hierarchy Process) to evaluate development and operation for maritime leisure. The evaluation hierarchical structure is structured by ISM(Interpretive structural modeling) and composed of five level. At the third level, It combine SWOT into the assessment system. Strength and Weakness are internal factors. Opportunities and threats are external factors. There are economic and maritime leisure development in the model. There are three development and operation investment as Third-Sector, company, local organization. According to the results, the participants perceive prefer to strength and opportunity and found that the priority for the development and operation for maritime leisure of Third-Sector.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.715-721
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• 2005

This paper proposes an evaluation model to assessment of development and operation for maritime leisure in Mokpo Port.. The proposed model is combination of SWOT(Strength, Weakness, Opportunity, Threat} and AHP(Analytic Hierarchy Process) to evaluate development and operation for maritime leisure. The evaluation hierarchical structure is structured by ISM(interpretive structural modeling} and composed of five level. At the third level, It combine SWOT into the assessment system Strength and Weakness are internal factors. Opportunities and threats are external factors. There are economic and maritime leisure development in the model. There are three development and operation investment as Third-Sector, company, local organization. According to the results, the participants perceive prefer to strength and opportunity and found that the priority for the development and operation for maritime leisure of Third-Sector.

• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.439-444
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• 2002

In this paper, we present both the link budget analysis according to system parameters and the cell coverage according to transmitter power and modulation scheme of digital MMDS among the wireless CATV system methods which is bated on the wireless internet service. Also, in this paper, we present C/I and number of subscriber according to splitting cell. In this paper, the cell coverage of which obtain the results according to both transmitter power from 0dBW to -9dBW and modulation scheme of QPSK, 16QAM and 64QAM based on link budget was analysis for system parameter of digital MMDS was able to provide from maximum 134km to minimum 4.3km. Also, in this paper, the number of subscriber of which obtain the results according to polarization wave, frequency of frequency reuse and C/I in 4. 6 and 8 sectors was able to provide from maximum 5,200DSI to minimum 1,300DSI.

• Railway Journal
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• v.17 no.3
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• pp.11-17
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• 2014